Post-stop-signal adjustments: inhibition improves subsequent inhibition

Performance in the stop-signal paradigm involves a balance between going and stopping, and one way that this balance is struck is through shifting priority away from the go task, slowing responses after a stop signal, and improving the probability of inhibition. In 6 experiments, the authors tested whether there is a corresponding shift in priority toward the stop task, speeding reaction time to the stop signal. Consistent with this hypothesis, stop-signal reaction time (SSRT) decreased on the trial immediately following a stop signal in each experiment. Experiments 2-4 used 2 very different stop signals within a modality, and stopping improved when the stop stimulus repeated and alternated. Experiments 5 and 6 presented stop signals in different modalities and showed that SSRT improved only when the stop stimulus repeated within a modality. These results demonstrate within-modality post-stop-signal speeding of response inhibition.     

Body Dissatisfaction and Disordered Eating in Three Cultures: Argentina, Brazil, and the U.S.

Body dissatisfaction and associated attitudes were studied in 18–24?years old women from universities in Rosario, Santa Fe, Argentina (N?=?118), Jo?o Pessoa, Paraíba, Brazil (N?=?81), and mid-Atlantic U.S. (N?=?102). Based on anecdotal reports, theoretical concerns, and empirical studies, we expected greater body dissatisfaction and negative body attitudes in our Argentine and Brazilian samples than in the U.S. sample. Body dissatisfaction was a significant problem in all samples, but we found few differences in levels of body dissatisfaction. The Argentine and Brazilian samples scored lower than the U.S. sample on measures associated with disordered eating, experienced less pressure to be thin, and were less likely to internalize the thin body ideal. Body shame was highest in the Brazilian sample and lowest in the Argentine sample. Cultural features in Argentina and Brazil that may offer some level of protection against the thin body ideal were discussed.     

Bright minds and dark attitudes: lower cognitive ability predicts greater prejudice through right-wing ideology and low intergroup contact

Despite their important implications for interpersonal behaviors and relations, cognitive abilities have been largely ignored as explanations of prejudice. We proposed and tested mediation models in which lower cognitive ability predicts greater prejudice, an effect mediated through the endorsement of right-wing ideologies (social conservatism, right-wing authoritarianism) and low levels of contact with out-groups. In an analysis of two large-scale, nationally representative United Kingdom data sets (N = 15,874), we found that lower general intelligence (g) in childhood predicts greater racism in adulthood, and this effect was largely mediated via conservative ideology. A secondary analysis of a U.S. data set confirmed a predictive effect of poor abstract-reasoning skills on antihomosexual prejudice, a relation partially mediated by both authoritarianism and low levels of intergroup contact. All analyses controlled for education and socioeconomic status. Our results suggest that cognitive abilities play a critical, albeit underappreciated, role in prejudice. Consequently, we recommend a heightened focus on cognitive ability in research on prejudice and a better integration of cognitive ability into prejudice models.     

Episodic and prototype models of category learning

The question of what processes are involved in the acquisition and representation of categories remains unresolved despite several decades of research. Studies using the well-known prototype distortion task (Posner and Keele in J Exp Psychol 77:353–363, 1968) delineate three candidate models. According to exemplar-based models, we memorize each instance of a category and when asked to decide whether novel items are category members or not, the decision is explicitly based on a similarity comparison with each stored instance. By contrast, prototype models assume that categorization is based on the similarity of the target item to an implicit abstraction of the central tendency or average of previously encountered instances. A third model suggests that the categorization of prototype distortions does not depend on pre-exposure to study exemplars at all and instead reflects properties of the stimuli that are easily learned during the test. The four experiments reported here found evidence that categorization in this task is predicated on the first and third of these models, namely transfer at test and the exemplar-based model. But we found no evidence for the second candidate model that assumed that categorization is based on implicit prototype abstraction.     

You don't act like you trust me: dissociations between behavioural and explicit measures of source credibility judgement

This study compared explicit and behavioural measures of source credibility judgements based on two factors: a source's past record of accuracy and its production of predictions that participants would like to believe. The former is considered to be a rational factor for judging credibility, while the latter is considered nonrational (i.e., it does not predict actual credibility). In Experiments 1 and 2, participants saw an equal number of predictions from two sources, one of which was either highly or slightly more accurate/desirable than the other. In Experiment 3, either one source was high accuracy and the other high desirability, or one source was higher on both measures. For all experiments, participants then saw new accurate and inaccurate predictions and said which source they thought was most likely to produce each (behavioural task). Participants then gave a percentage rating for each source's perceived accuracy (explicit judgement task). Participants showed sensitivity to past accuracy differences using both tasks, but not to the size of the differences. Desirability influenced performance only on the behavioural task. However, when the two factors conflicted, participants responded solely using past accuracy information. Behaviours reflect source credibility judgements based on both rational and irrational factors, but participants appear to be both more strongly influenced by the rational factor and more aware of that influence.